Spatial single cell profiling using imaging mass cytometry - inflammatory versus penetrating Crohn's disease

BACKGROUND AND AIMS

Fistula formation is a major complication in Crohn's disease (CD) and the role of the immune cell compartment remains to be elucidated. Thus, we compared the immune-cell compartment of CD fistula to inflammatory CD colitis using imaging mass cytometry and immunofluorescence.

METHODS

A 36-marker panel including structural, functional and lineage markers for use in imaging mass cytometry (IMC) was established. This panel was applied to analyze paraffin-embedded CD fistula tract (n=11), CD colitis (n=10), and colon samples from non-inflamed controls (n=12). Computational methods for cell segmentation, dimensionality reduction and cell type clustering were used to define cell populations for cell frequency, marker distribution and spatial neighborhood analysis. Multiplex immunofluorescence was used for higher resolution spatial analysis.

RESULTS

Analysis of cell frequencies in CD fistulas compared to CD colitis and control colonic samples revealed a significant increase in neutrophils, effector cytotoxic T cells and inflammatory macrophages in CD fistula samples, whereas regulatory T cells were decreased. Neutrophils in CD fistula expressed significantly more matrix metalloproteinase 9 (MMP9), correlating to extracellular matrix remodeling. Neighborhood analysis revealed a strong association between MMP9+ neutrophils and effector cytotoxic T cells in both CD fistulas and colitis.

CONCLUSIONS

This study presents the first highly multiplexed single cell analysis of the immune-cell compartment of CD fistulas and their spatial context. It links immune cell dynamics, particularly MMP9+ neutrophils, to extracellular matrix remodeling in CD fistulas, offering insights into the complex network of cellular interactions and potential therapeutic targets for CD complications.

Minimal-invasive approach for penetrating Crohn's disease is not associated with increased complications

Background

Laparoscopic surgery for penetrating Crohn’s disease (CD) still remains highly conflicting due to a lack of sufficient data. Therefore, the following large study was designed to compare postoperative outcomes after minimal-invasive resections for penetrating and non-penetrating CD.

Methods

Consecutive patients, who underwent laparoscopic intestinal resection for symptomatic CD at a tertiary academic referral center, were included. Patients were divided according to perioperative findings in penetrating and non-penetrating type of disease. All clinical data were obtained from an institutional database and analyzed retrospectively.

Results

Of 234 patients enrolled, 101 patients [females: n = 54 (53.5 %)] were operated on for non-penetrating CD and 133 patients [females: n = 50 (37.6 %)] for penetrating CD. Fistulas (p < 0.001), inflammatory mass (p < 0.001) and abscess formation (p < 0.001) were observed more frequently in the perforating group. Ileocolic resections were performed predominantly in both groups [perforating CD: n = 110 (82.7 %), non-perforating CD: n = 82 (81.2 %)], with more complex resections (>1 intestinal resection) found in perforating CD (p < 0.001). Conversion rates did not differ significantly. Notably, 30-day postoperative morbidity was comparable for both groups [perforating CD: n = 20 (15 %), non-perforating CD: n = 19 (18.8 %), p = 0.44]. Postoperative complication rates graded according to the Clavien–Dindo classification showed no difference too (p = 0.49).

Conclusion

Laparoscopic surgery can be conducted safely in selected patients with penetrating CD without increasing the risk of postoperative complications. This finding needs to be implemented in future guidelines.